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An economic assessment of the amenity An economic assessment of the amenity benefits associated with alternative benefits associated with alternative

coastal defence options.coastal defence options.Dr Mike Christie and Oliver ColmanDr Mike Christie and Oliver Colman

University of Wales AberystwythUniversity of Wales Aberystwyth

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Current coastal defenceCurrent coastal defence

Wooden groynes – now at end of their useful life

Seawall

Shingle bank

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New ‘traditional’ coastal defence New ‘traditional’ coastal defence options for Borthoptions for Borth

Replace wooden groynesReplace wooden groynes

Rock groynesRock groynes

Raise height of seawallRaise height of seawall

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An alternative coastal defence option: An alternative coastal defence option: multi-purpose reefmulti-purpose reef

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Research aim and methodResearch aim and method

Aim: To examine local residents AMENITY Aim: To examine local residents AMENITY values for alternative coastal defence values for alternative coastal defence options. options.

Method: Choice experimentsMethod: Choice experiments

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Choice experiment attributes and Choice experiment attributes and levelslevels

VisualVisual AppearanceAppearance No changeNo change Rock GroynesRock Groynes Offshore ReefOffshore Reef

SeawallSeawall NoNo changechange Raised wallRaised wall

Surf ConditionsSurf Conditions No changeNo change ImprovedImproved

Conditions for Family Beach ActivitiesConditions for Family Beach Activities No changeNo change Safer conditionsSafer conditions

Increased taxationIncreased taxation 6 levels6 levels

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Choice task: Borth exampleChoice task: Borth exampleOPTION A OPTION B STATUS QUO

Visual appearance Structures made from large rocks would replace the timber

groynes.

Existing timber groynes with shingle

bank

Existing timber groynes with shingle

bank

Height of seawall No change in the height of the wall

Wall raised by 1 metre to reduce the

likelihood of overflow

No change in the height of the wall

Surf conditions Conditions for surfing would remain unchanged

Conditions for surfing would improve

Conditions for surfing would remain unchanged

Beach conditions for family amenity

Safer conditions for beach activities

Conditions for beach activities would

remain unchanged

Conditions for beach activities would

remain unchanged

Annual tax increase You will pay an extra £15.00

tax annually over a 5 year period

You will pay an extra £6.00

tax annually over a 5 year period

Your tax bill will not be increased

Choice A [ ] B [ ] SQ [ ]

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Results: RPL modelResults: RPL modelNon random parameters in utility function

ASC_SQ -1.257* (-7.851)

Visual_rock_groyne -0.441* (-6.002)

Visual_reef 0.746* (7.381)

Family_amenity 0.495* (4.399)

Tax -0.015* (-4.839)

Random parameters in utility function

Seawall 0.305 (0.987)

Improved_surf -0.029 (-0.181)

Heterogeneity in Mean, parameter : variable

Seawall_Upper -1.005* (-1.884)

Surf_surfer 1.116* (3.387)

LL model -796.956

LL constants only -1054.668

Pseudo-R2 24.43

Correct predictions 0.462

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Results: Implicit pricesResults: Implicit pricesAttributes RPL

Visual_timber_groynes (all residents)-£19.82 *

(7.23)

Visual_rock_groyne (all residents)-£28.66 *

(8.06)

Visual_reef (all residents)£48.49 *

(12.84)

Seawall (all residents)£19.81(20.12)

Seawall (Upper Borth only)-£45.45 *

(30.49)

Improved_surf (all residents)-£1.95(10.85)

Improved surf (Surfers only)£70.59 *

(21.02)

Family_amenity (all residents)£32.14 *

(10.09)

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Key observationsKey observations

Visual timber groyne: negativeVisual timber groyne: negative Visual rock groyne: negativeVisual rock groyne: negative Visual reef: positiveVisual reef: positive

Family amenity: positiveFamily amenity: positive

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Key observationsKey observations

‘‘Seawall’ and ‘improved surf were insignificantSeawall’ and ‘improved surf were insignificant

Seawall – Upper Borth interaction is significant: Seawall – Upper Borth interaction is significant: Lower Borth want generally want sea wallLower Borth want generally want sea wall Upper Borth don’t.Upper Borth don’t.

Improved surf – Surfer interaction is significant:Improved surf – Surfer interaction is significant: Surf conditions now significant for surfers, who want Surf conditions now significant for surfers, who want

improved surfimproved surf Non-surfers still insignificantNon-surfers still insignificant

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Amenity value associated with Amenity value associated with coastal protection proposals at Borthcoastal protection proposals at Borth

Coastal defence option Compensating surplus value

(£ per household)

Replace existing groynes with timber groynes0

Replace existing groynes with rock groynes-8.84

Replace existing groynes with a multi-purpose reef (excluding surf improvements) 98.5

Replace existing groynes with a multi-purpose reef (including surf improvements) 171.04

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ConclusionsConclusions

The multi-purpose reef option provides The multi-purpose reef option provides significant amenity benefits over traditional significant amenity benefits over traditional coastal defence options.coastal defence options.

Mixed views with regard to raising the Mixed views with regard to raising the seawall.seawall.

Policy makers should consider non-market Policy makers should consider non-market values in coastal defence proposals in the values in coastal defence proposals in the future.future.

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Thank you for your attention.

Any Questions